Amyloidosis and Alzheimer&#39;s disease diagnostic assay and reagents therefor

ABSTRACT

The presence and location of amyloid deposits in an organ or body area of a patient is effected by intravenous administration of novel radioactive iodine-labeled amyloid binding compounds and preferably  123  I-labeled compounds to the patient and sensing radiation emitted from the organ or body area. Novel non-radioactive iodine substituted amyloid binding compounds and amyloid binding compounds which are readily iodinated are further aspects or the invention.

RELATIONSHIP TO COPENDING APPLICATION

This application is a division of copending application Ser. No.178,402, filed Apr. 6, 1988, now U.S. Pat. No. 4,933,156, acontinuation-in-part of copending application Ser. No. 35,837, filedApr. 8, 1987, now abandoned.

FIELD OF THE INVENTION

This invention relates to novel compounds and their use for diagnosingAlzheimer's disease and other diseases characterized by presence ofamyloidosis. In particular, this invention relates to compounds whichselectively bind to amyloid structures in the body and which can bereadily iodinated, the radioactive iodine substituted derivativesthereof, and the diagnosis of amyloid associated diseases with theradiolabeled derivatives.

BACKGROUND OF THE INVENTION

Alzheimer's disease (AD) is the most frequent cause of dementia in theUnited States and is currently the fourth most common cause of death.The disease can strike persons as young as 40-50 years of age andaffects over three million individuals. The origin of the disease isunknown, and because the presence of the disease is difficult todetermine without invasive biopsy, its time of onset is unknown. Thecondition is characterized by impairments in memory, cognition, languageand mobility, and these conditions become progressively more severe withtime. Neuropathological examination of the brains of affectedindividuals discloses the presence of several characteristicabnormalities: neuritic plaques consisting of abnormal neuronal axonterminals associated with a core of extra-cellular amyloid protein;neurofibrillary tangles comprised of bundles of cross-linked proteinfilaments which have accumulated in the neuronal cell bodies; andgranulovacuolar degeneration which consists of intercellular vacuolespresent mostly in hippocampal pyramidal neurons.

In addition, a strong correlation has been found between the density ofamyloid-containing plaques in the cortex of AD victims at autopsy andthe severity of their cognitive defects. Until recently, diagnosis of ADwas based on clinical criteria involving clinical diagnosis of physicaland mental impairment and determination that other diseases with thesame characteristics were not the cause of the impairments.

Post-mortem slices of brain tissue of victims of Alzheimer's diseasehave been shown to exhibit the presence of amyloid (an amorphous mixtureof protein, carbohydrate and lipid complexes) in the form ofproteinaceous extracellular cores of the neuritic plaques characteristicof the disease. The amyloid cores of such senile plaques are composed ofmicroscopic fibrils whose protein is arranged in a predominatelyβ-pleated sheet configuration. AD plaque amyloid appears to contain oneor more characteristic protein constituents, and some have been isolatedand purified. Vascular deposits of anyloid fibrils in non-Alzheimer'samyloidoses have been shown to be derived from an abnormal serum proteinby Glenner, G. New Eng.J.Med. 302:1283-1291 (1980). The genetic locusfor the amyloid protein has been localized to chromosome 21 as reportedby George-Hyslop et al, Science. 235:885-890 (1987) and Tanzi et al,Science. 235:880-884 (1987). Isolation and partial sequencing of thegene has been reported by Goldaber et al, Science. 235:877-880 (1987),and partial sequencing of at least one of the amyloid AD proteins hasbeen reported by Glenner, G. et al, Biochemical and BiophysicalCommunications. 120:885-890 (1984).

More recently, immunoassay methods have been developed for detecting thepresence of neurochemical markers in AD patients and to detect an ADrelated amyloid protein in cerebral spinal fluid as summarized byWarner, M. Anal.Chem. 59:1203A-1204A (1987). These new methods, whilebeing a major advance over the earlier method for diagnosing AD, havenot proven to detect AD in all patients, particularly at early stages ofthe disease.

Because Alzheimer's disease is slow in onset, can first appear as earlyas the fifth decade of life, and is progressive in nature, theefficiency of a cure could critically depend upon early detection.Additionally, the value of any new therapy in alleviating of curing thedisease could be better ascertained if a rapid, safe and effectivediagnostic procedure were available to monitor the progress of ADpatients following treatment.

The most advanced diagnostic tests for AD detection developed to datedetermined the AD-assoalleviating of curing the disease could be betterascertained if a rapid, safe and effective diagnostic procedure wereavailable to monitor the progress of AD patients following treatment.

The most advanced diagnostic tests for AD detection developed to datedetermined the AD-associated amyloid protein in spinal fluid using anantibody binding selectively therewith. A spinal tap procedure isrequired to obtain a sample for testing. Such a procedure is painful,invasive, potentially dangerous, costly, and the patient often must behospitalized overnight for observation.

Cerebrovascular amyloidosis has been observed only in patients withAlzheimer's disease and adult Down's syndrome by Glenner, G., COLDSPRING HARBOR SYMPOSIUM. pp 137-144 (1983) and a familial Icelandiccerebrovascular amyloidosis syndrome by Cohen, et al, J.Exp.Med.158:623-628 (1983). The latter conditions have characteristics otherthan dementia which are easily determined and can be distinguished fromAD. Amyloid thus can be used as a chemical marker for the disease.Non-cerebral amyloid is an extracellular, amorphous, eosinophilicmaterial most commonly arising as a consequence of chronic inflammatorydisease of long standing. Spleen, liver, kidneys, adrenals, lymph nodesand pancreas are the organs usually affected. Gratuitously, amyloid ofthis type was referred to as secondary or typical. Primary, or atypicalamyloid is usually found in muscle and the cardiovascular system, butmay be more conveniently diagnosed in rectal, skin or gingival biopsies.It arises in the basence of any obvious predisposing inflammatorydisease.

DESCRIPTION OF THE PRIOR ART

Congo Red and other benzidine-type dyes such as Congo Corinth,Benzopurpuri 4B, Vital Red, and Trypan Blue stain amyloid selectively asreported by Puchtler, H. et al, "On the binding of Congo Red byamyloid." J.Histochem.Cytochem. 10:35-364 (1962). The stained amyloid ischaracterized by a dichroic appearance, the Congo Red stained amyloidshowing a green polarization color. Puchtler, H. et al, "Application ofthiazole dyes to amyloid under conditions of direct cotton dyeing:correlation of histochemical and chemical data." Histochem. 77:431-445(1983) describes amyloid staining and fluorescence characteristics ofPhorwhite BBU, Thioflavine S, Congo Red, Diphenyl Brilliant Yellow 8G,Clayton Yellow, Thiazol Yellow, Thioflavin T, Seto Flavine T, Erie Pink2B, Thiazine Red R, Geranine G, Piphenyl Chlorine Yellow FF, DirectYellow 29, Sirius Supra Yellow 5G and Solophenyl Yellow FFL. Studies ofthiazole dyes, Primulin, Thioflavine S and Thioflavine T as amyloidstaining dyes were reported by Kelenyi, G., "On the histochemistry ofazo group-free thiazole dyes." J.Histochem.Cytochem. 15:172-180 (1967).

The dichroic binding was determined to be the result of the β-pleatedsheet structure which is the common characteristic of amyloid proteins,independently of the diverse chemical structure of the various amyloidtissues by Glenner, G. "Amyloid deposits and amyloidosis: Theβ-fibrilloses (first of two parts). New England, J. Med. 302:1283-1292(1980).

The non-invasive techinique for diagnosis of amyloidosis comprising theCongo Red uptake method of Bennhold was described as inconstant and ofdubious diagnostic value by Glenner, G., "Amyloid deposits andamyloidosis: the β-fibrilloses (second of two parts)." New EnglandJ.Med. 302:1333-1343 (1980). He also describes and lists the diseasesassociated with amyloidosis and their diverse origin. The common factorfor the diseases was the β-pleated structure of the amyloid proteins,and the causes for these deposits appeared to be diverse.

Efforst to improve the method of Bennhold first studies the effects ofdifferent dosing schedules and selecting different times for determiningdepletion of the Congo Red levels in seruym by Unger, P. et al, "Studyof the disappearance of Congo Red from the blood of non-amyloid subjectsand patients with amyloidosis." J.Clin.Invest. 27:111 (1948). In effortsto reduce the amount of Congo Red required in this procedure, Knorpp, C.et al, "Radiosulfur (S³⁵) labeled Congo Red dye." J.Nucl.Med. 1:23-30(1960) synthesized and radiosulfur-labeled Congo Red dye andinvestigated it use in diagnosing amyloidosis. ³⁵ S (half life 87.2days) was selected as the only inorganic tracer suitable for theintended synthesis. The plasma level was then quantified by measuringthe radioactive label.

Tubis, M. et al, "The preparation and use of radioiodinated Congo Red indetecting amyloidosis." J.Amer.Pharm.Ass. 49:422 (1960) describedsynthesis of a Congo Red substituted at one or more of the 3,3',5 and 5'positions. In one procedure, the Congo Red was prepared by diazotizingthe radioiodinated benzidines and coupling with sodium naphthalate. Inanother procedure of direct radioiodination, the Congo Red was refluxedin a chloroform solution containing 0.0163 mg of ¹³¹ ICI for 8 to 12hours followed by dialysis or column treatment with an anion exchangeresin in either the OH or Cl form. These methods are not suitable forpreparing a radiolabeling with ¹²³ I which has a half-life of 13.1hours. ¹²³ I has an optimum emission spectrum of 0.1590 MeV representing83%. Other radioactive forms of iodine such as ¹³¹ I have longerhalf-lives, increasing the patient exposure to radiation and/or morethan one significant emission energy spike, severely limiting the valueof diagnostic imaging. Tubis, M. et al, "The use of radioiodinated CongoRed in the study of amyloidosis." Nuklear Medizin. 3:25-38 (1962)studied the use of ¹³¹ I-labeled Congo Red in the diagnosis ofamyloidosis in humans. The use of the radiolabeled Congo Red permittedeasy quantification of the disappearance of the dye. However, ¹³¹ I hasmultiple decay energy emissions and an undesirably long half-life of 8.1days, and it is not suitable for routine in vivo diagnostic use. Theradioactive label was used in serum depletion and photoscans of amyloidaffected organs.

Kaye, M. et al, "A radioiodinated azo dye with affinity for amyloid: apreliminary report." Canad.Med.Ass.J. 30:694 (1964) reported developinga Trypan Blue substituted at the 8-position with a radioactive iodinecompound using a "Sandmeyer reaction". Use of the product in selectivelystaining amyloid tissue and metabolic studies were reported.

OBJECTS AND SUMMARY OF THE INVENTION

One subject of this invention is the provision of compounds whichselectively bind with amyloid in vivo and which can be readily labeledwith radioactive iodine.

It is another object of this invention to provide radioactive iodinelabeled amyloid binding compounds which can be administered for thediagnosis of Alzheimer's disease and other amyloidosis.

It is still a further object of this invention to provide a non-invasivediagnostic method for diagnosing diseases characterized by amyloidosisusing radiolabeled compounds which selectively bind with amyloidtissues.

The ardioiodinated compounds of this invention are selected from thegroup of compounds represented by Formula, I, II, III and IV and theirwater-soluble, pharmaceutically acceptable salts wherein I^(*)represents a radioactive iodine isotope. The compounds of Formula I arerepresented by the following formula: ##STR1## wherein R₁ is amino orhydroxy;

R₂, R₃, R₄, R₅ and R₆ are hydrogen or sulfo, with the provision that notmore than two of R₂, R₃, R₄, R₅ and R₆ are sulfo and sulfo is notpresent on adjacent carbons R₇ is hydrogen or hydroxy;

R₈, R₉ and R₁₀ are hydrogen, hydroxy, carboxy or lower alkyl estersthereof, methyl, or methoxy;

R₁₂ and R₁₄ are each independently hydrogen, methyl, chloro, methoxy,carboxy or a lower alkyl ester thereof, or nitro; and

R₁₃ and R₁₅ are each independently hydrogen or sulfo.

The compounds of Formula II are represented by the following formula:##STR2## wherein R₂₀, R₂₄, R₂₅ and R₂₉ each independently are hydrogen,hydroxy or amino, with the proviso that R₂₄ is not the same as R₂₀ andR₂₉ is not the same as R₂₅ ;

R₂₁, R₂₂, R₂₃, R₂₆, R₂₇ and R₂₈ each independently are hydrogen orsulfo, with the proviso that not more than two of R₂₁, R₂₂, and R₂₃ issulfo and not more than two of R₂₆, R₂₇ and R₂₈ is sulfo, and sulfo isnot present on adjacent carbons;

R₃₀ and R₃₂ are each independently hydrogen, methyl, chloro, methoxy,carboxy or a lower alkyl ester thereof, or nitro;

R₃₁ and R₃₃ are each independently hydrogen or sulfo;

X₁, X₂, X₃ and X₄ are each independently hydrogen or I^(*), with theproviso that X₁ is hydrogen when R₂₁ is sulfo, X₂ is hydrogen when R₂₂and R₂₃ is sulfo, X₃ is hydrogen when R₂₆ is sulfo, and X₄ is hydrogenwhen R₂₇ or R₂₈ is sulfo.

The compounds of Formula III are represented by the following formula:##STR3## wherein R₄₀ and R₄₁ are hydrogen, hydroxy, or amino, and R₄₀and R₄₁ are not the same group;

R₄₂, R₄₃, R₄₄, R₄₅, and R₄₆ are hydrogen or sulfo; one or two of R₄₂,R₄₃, R₄₄, R₄₅, and R₄₆ are sulfo; and sulfo is not present on adjacentcarbons; and

R₄₇ is hydrogen, methyl or carboxy.

The compounds of Formula IV are represented by the following formula:##STR4## wherein R₅₀ is hydrogen or sulfo;

R₅₁ is methyl or carboxy; and

R₅₂, R₅₃ and R₅₄ each are hydrogen, hydroxy, carboxy or lower alkylesters thereof, methyl, or methoxy.

In compounds of this invention, the preferred radioactive form of iodineis ¹²³ I.

The non-radioactive iodine and uniodinated precursors of the Compoundsof Formulas I, II, III and IV wherein I^(*) is replaced by hydrogen ornon-radioactive I are also intermediate compounds of this invention.

The method of this invention for determining the presence and locationof amyloid deposits in an organ or area of a patient comprisesintravenous administration of an imaging effective quantity of acompound of Formulas I, II, III or IV, or a pharmaceutically acceptable,water-soluble salt thereof to the patient; and sensing radiation emittedfrom the organ or area being examined.

DETAILED DESCRIPTION OF THE INVENTION

The method of this invention for determining the presence and locationof amyloid deposits in an organ or area of a patient comprisesintravenous administration of an imaging effective quantity of acompound of Formulas I, II, III or IV 9"Imaging Compounds"), or apharmaceutically acceptable, water-soluble salt thereof to the patient;and sensing radiation emitted form the organ or area being examined.

The imaging compounds are formed from precursor compounds which can bereadily and quickly iodinated with I^(*).

The bisdiazobenzidine compounds precursors of Formula VII are formedfrom the respective, known diamino compounds of Formula VI by thefollowing reaction sequence. ##STR5## wherein R₁₂, R₁₃, R₁₄ and R₁₅ areas previously described with respect to Formula I and Y is Cl³¹ or BF₄⁻. The diamino compounds of Formula VI are known in the art. These arediazotized by reaction with two molar equivalents of sodium nitrite inaqueous acid solution (HCl, H₂ SO₄, or the like) to yield the diazocompounds of Formula VII, a starting material for several groups ofdiazo compounds of this invention.

In general, all of the aniline and benzidine compounds described hereincan be diazotized in aqueous acid (e.g., HCl, H₂ SO₄, etc.) with sodiumnitrite (NaNO₂). One equivalent of acid per amine group is used togenerate the acid salt. The mixture is maintained at -5 C. to 15° C. inan ice/solvent bath. One additional equivalent of acid per amine groupis added to generate nitrous acid from added sodium nitrite. The aqueousdiazonium salt is used within 10 to 20 minutes of preparation.

An alternate method of diazotization which can be used for neutralaromatic amines comprises the reaction of the amine with 1.5 to 2 molarequivalents of boron trifluoride etherate in THF at -5° C. to 15° C.,followed by the addition of one molar equivalent of t-butyl nitrite peramine group. The resulting tetrafluoroborate salt precipitates from thesolution and can be isolated and stored at temperatures below 0° C. Thesalts can be dissolved in a polar organic solvent such as alcohol andadded to the selected substrate for diazo coupling.

The compounds of Formula I are formed in two stages. The diazo compoundsof Formula VII are reacted with one molar equivalent of the sulfonicacid compounds of Formula VIII in aqueous solution. ##STR6## In theFormulas VIII and IX, R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₁₂, R₁₃, R₁₄ and R₁₅are as identified above with respect to Formula I and Y is an anion suchas Cl⁻ or BF₄ ⁻, the reaction product is then reacted with a molarequivalent of an iodophenyl compound of Formula X, yielding thecompounds of Formula XI'. ##STR7## In Formulas X and XI, R₁, R₂, R₃, R₄,R₅, R₆, R₇, R₈, R₉, R₁₀, R₁₂, R₁₃, R₁₄ and R₁₅ are as identified abovewith respect to Formula I.

The diazo coupling reactions used to form the compounds of thisinvention involve the coupling of diazo compounds to aromatic amines andphenols. In general, the coupling reactions are carried out at -5° C. to20° C. in aqueous or aqueous alcohol solutions over a reaction period offrom 10 minutes to 2 hours. The positions of coupling are determined byboth steric factors and pH of the reaction solution. To achieve couplingortho or para to an amine group, the solution is maintained in a pHrange of about from 3 to 7. To achieve coupling ortho or para to ahydroxy group, the solution is maintained at pH from 8 to 11. When twodiazo couplings are to be effected, for example with bisdiazobenzidines,the less reactive substrate is preferably coupled first. If acid andbase couplings are required, the acid coupling is effected first toavoid the excessive decomposition of the diazonium group which can occurin basic solutions. When more than one activated ring position isavailable for coupling, the coupling usually occurs at the lesssterically hindered position. Details of diazo coupling reactions areprovided by Zollinger, H., AZO and DIAZO CHEMISTRY: ALIPHATIC ANDAROMATIC COMPOUNDS. New York: Interscience Publishers (1961), the entirecontents of which are hereby incorporated by reference.

The radioiodinated compounds of Formula I are formed by iodide exchangeof the compounds of Formula XI in absolute ethanol using NaI^(*), whereI^(*) represents a radioactive form of iodine.

    (XI)+NaI.sup.* →(I)

In general, any of the azo dyes with an available activated aromaticring position can be directly iodinated by electrophilic substitution.This is effected by reacting the dye with a suitable source of iodinesuch as iodine monochloride (ICI), or a 1:1 mixture of NaI and anoxidizing agent such as Chloramine-T, t-butyl hypochlorite, hydrogenperoxide, and the like, in a polar solvent such as an alcohol, DMF,water, etc. The iodination can occur either para or ortho to a hydroxyor amine group.

In general, the azo dyes can be radioiodinated either by directiodination ;of non-iodinated azo dyes, as described above, using asource of radioactive iodine (¹²⁵ I, ¹²³ I, etc.) and preferably ¹²³ Ior by iodine exchange with non-radioactive iodine groups on dyes usingsources of the radioactive iodine, as described above forradioiodinating the iodine substituted compounds of Formula XI. Theexchange is carried out in a polar solvent such as alcohols, DMF, water,acetic acid, and the like at 100° C. to 200° C. in a sealed ampule forfrom 30 minutes to 24 hours. The concentration of dye in 1 to 2 mL ofsolvent is at least 0.1 M (or saturated), with 0.2 to 10 mCi of carrierfree radioactive iodide as NaI^(*).

The anionic acid dyes (sulfonates, carboxylates, etc.) can be purifiedby reverse phase thin layer chromatography (RPTLC) on C₁₈ -silica gelplates such as (20×20 cm Whatman KC18F, 200 μm thick) eluting with amixture of 80:20:0.2 v/v/v methanol:water:trifluoroacetic acid. Byrepeating the above procedure on the same sample, radiochemical puritiesgreater or equal to 99 percent can be obtained.

The non-ionic dyes can be purified by normal phase thin layerchromatography (NPTLC) ON 60A silica gel plates (Whatman Silica 60A (60Agnstroms), PK6F 20×20 cm, 250 μm thickness) eluted withdichloromethane/methanol mixtures of 50:50 to 90:10 v/v, ortoluene/ethyl acetate mixtures of 80:20 v/v.

Purifications can also be carried out by HPLC or gravity column methods.A complete description of dye chromatography is given by Venkataraman,K., THE ANALYTICAL CHEMISTRY OF SYNTHETIC DYES. New York: John Wiley &Sons (1977), the entire contents of which are hereby incorporated byreference in their entirety.

The compounds of Formula II are synthesized by the following procedure.

The substituted naphthalene sulfonic acids of Formula XII are knowncompounds. The bis-diazobenzidine of Formula VII is added to the aqueoussolution containing at least two molar equivalents of the naphthalenesulfonic acid of Formula XII at pH 4 to 6.5 to form the amyloid bindingdiazo compounds of Formula XIV. ##STR8## In Formulas XII and XIII, R₂₀,R₂₁, R₂₂, R₂₃, R₂₄, R₂₅, R₂₆, R₂₇, R₂₈, R₂₉, R₃₀, R₃₁, R₃₂, and R₃₃ areas described above with respect to Formula II. The products are purifiedby conventional procedures such as are described above.

The compounds of Formula XIII are readily iodinated by reaction withiodine monochloride or a 1:1 mixture of Chloramine-T and sodium iodidein aqueous methanol for one hour, the molar ratios of the iodinecompound determining whether the reaction product of Formula XIV is tobe mono-iodinated or di-iodinated. ##STR9## In Formula XIV, R₂₀, R₂₁,R₂₂, R₂₃, R₂₄, R₂₅, R₂₆, R₂₇, R₂₈, R₂₉, R₃₀, R₃₁, R₃₂, R₃₃, X₁, X₂, X₃and X₄ are as described above with respect to Formula II.

In the above procedure, the iodine source can be radioactive iodine todirectly yield the compounds of Formula II. Alternatively, if anon-radioactive form of iodine is used and the iodine substituent of thecompounds of Formula XIV are non-radioactive, the product can be readilylabeled with radioactive iodine by iodide exchange in absolute ethanolusing NaI^(*) as described above.

    (XIV)+NaI.sup.* →(II)

The products are purified by conventional procedures as described above.

The compounds of Formula III can be synthesized by reacting a compoundof Formula VIII with the diazoiodobenzene of Formula XV according to thefollowing procedure to form the iodinated diazo amyloid bindingcompounds of Formula XVI. ##STR10## In Formulas XV and XVI, R₄₀, R₄₁,R₄₂, R₄₃, R₄₄, R₄₅, R₄₆ and R₄₇ are as described above with respect toFormula III.

The diazo coupling reaction is carried out as described above.

In the above procedure, the iodine source can be radioactive iodine todirectly yield the compounds of Formula III. Alternatively, if anon-radioactive form of iodine is used and the iodine substituent of thecompounds of Formula XVI are non-radioactive, the product can be readilylabeled with radioactive iodine by iodide exchange in absolute ethanolusing NaI^(*) as described above.

    (XVI)+NaI.sup.* =l →(III)

The products are purified by conventional procedures as described above.

The compounds of Formula IV can be prepared by the following procedures.The compounds of Formula XVII are known in the art. They are diazotizedby the general procedure described above to yield the diazocompounds ofFormula XVIII. ##STR11## In Formulas XVII and XVIII, R₅₁ and R₅₂ are asdescribed above with respect to Formula IV, and Y₁ is an anion such asCl⁻, HSO₄ ⁻, BF₄ or the like.

The diazo compound of Formula XVIII is then reacted with the iodobenzenecompounds of Formula XIX to yield the amyloid binding diazo compounds ofFormula XX. ##STR12## In Formulas XIX and XX, R₅₀, R₅₁, R₅₂, R₅₃ and R₅₄are as described above with respect to Formula IV.

In the above procedure, the iodine source can be radioactive iodine todirectly yield the compounds of Formula IV. Alternatively, if anon-radioactive form of iodine is used and the iodine substituent of thecompounds of Formula XVI are non-radioactive, the product can be readilylabeled with radioactive iodine by iodide exchange in absolute ethanolusing NaI^(*) as described above.

    (XX)+NaI.sup.* →(IV)

The products are purified by conventional procedures as described above.

The radioactive agents can be administered by routine procedures. Theycan be administered orally as solids, solutions or suspensions, orinjected intravenously in the form of standard aqueous solutions such asdescribed by REMINGTON'S PHARMACEUTICAL SCIENCES. 15th Ed., Easton: MackPublishing Co. pp 1405-1412 and 1461-1487 (1975) and THE NATIONALFORMULARY XIV. 14th Ed. Washington: American Pharmaceutical Association(1975), the contents of which are hereby incorporated by reference. Suchsolutions or suspensions can contain conventional, pharmaceuticallyacceptable, non-toxic excipients and additives such as salts, buffers,preservatives, and the like. After sufficient time has lapsed for thereagent to reach to area of the body being examined, for example from 30minutes to 48 hours, the area of the patient under diagnosis is examinedby routine imaging techniques such as SPECT and planar scintillationimaging. The distribution of the bound radioactive isotope and itsdecrease with time is monitored. By comparing the results with dataobtained from studies of clinically normal individuals, the presence ofcranial or other site deposits of amyloid can be determined, and thediagnosis of Alzheimer's disease (cranial) or other amyloidosis therebyconfirmed.

This invention is further illustrated by the following specific butnon-limiting examples. Temperatures are given in degrees Centigrade andpercentages as weight percents unless otherwise specified. Procedureswhich have been previously carried out are presented in the past tense,and procedures which are being constructively reduced to practice inthis application are presented in the present tense.

EXAMPLE 1 Radioiodinated Benzo Orange R (IBOR)

Technical grade Benzo Orange R (BOR, Pfalz and Bauer) was purified byextraction with methanol and rotoevaporation to dryness, giving a 25-30%yield of red powder.

BOR (0.10 g, 0.16 mmole) was dissolved in 20 mL of anhydrous methanolgiving a deep red solution. To this solution was added 0.0124 g (0.16mmole) or non-radioactive sodium iodide and 0.09 mCi of na¹²⁵ I. Afterall solids were dissolved, Chloramine-T tris hydrate (0.45 g, 0.16mmole, Kodak Chemical Co.) in 1 mL of methanol was added with vigorousstirring, the solution was rotoevaporated to dryness. The IBOR waspurified by preparative RPTLC with a radiochemical yield of 12%.

Repeating this method using Na¹²³ I yields the radiolabeled IBOR,4-amino-3-(4-(1-carboxy-2-hydroxy-3-¹²³I-5-phenyldiazo)biphen-4'-yldiazo)-naphthalene-1-sulfonic acid.

EXAMPLE 2 Radioiodinated Benzo Orange R (IBOR)

In alternate iodination method, BOR (0.50 g, 0.82 mmol) was slurried in50 ml of anhydrous methanol. A solution of ICl (0.14 g, 0.86 mmol) in0.5 mL of methanol was added with vigorous stirring, resulting in a darkred-brown solution. After 1 hr of stirring, the product was isolated byrotoevaporation. Purification of the IBOR was accomplished bypreparative RPTLC with a yield of 70-90%. ¹ HMNMR (D₆ -DMSO, 250 MHz)delta 8.74 (d, naphthyl-H), 8.43 (d, naphthyl-H) 8.20-8.32 (S,S,S,naphthyl-H, phenyl-H, phenyl-H), 8.10 (d, benzidine-H), 7.89-7.99(d,d,d, benzidine-H), 7.73 (S, --NH₂), 7.55 (t,t, naphthyl-H).

This method was repeated using BOR (0.25 g, 0.041 mmol) in 2.5 mL ofmethanol. Addition of ICl (0.0067 g, 0.042 mmol) in 0.25 mL of methanolcontaining 0.20 mCi na¹²⁵ I gave the radiolabeled product in aradiochemical yield of 32%.

Repeating this procedure but replacing Na¹²⁵ I with Na¹²³ I yields thecorresponding ¹²³ IBOR product.

EXAMPLE 3 Radioiodinated Benzo Orange R (IBOR)

In a radiolabelling by iodide exchange, IBOR (10 mg, 0.014 mmol) isslurried in 1 mL of absolute ethanol in a high pressure reaction flaskfitted with a teflon cap. Na¹²⁵ i, 0.1-10 mCi is added and the flasksealed. The mixture is heated to 150° C. for 6-18 hr. The product ispurified by preparative RPTLC.

Repeating this procedure with Na¹²³ I yields the corresponding ¹²³ Ilabeled product.

EXAMPLE 4 Diazobiphenyl Compound, Formula VII

3,3-Dimethoxybenzidine (0.98 g, 4 mmole) was slurried in 20 mL of watercontaining 2 mL of 12 M HCl at 0°C. Sodium nitrite (0.55 g, 8 mmole) in5 mL water was added with stirring, yielding the chloride salt of4,4'-bisdiazo-3,3'-dimethoxybiphenyl.

EXAMPLE 5 Diazobiphenyl Compounds, Formula VII

Repeating the procedure of Example 4, but replacing3,3'-dimethoxybenzidine with benzidine, 3,3'-dichlorobenzidine,3,3'-dimethylbenzidine, 2,2'-disulfobenzidine and3,3'-dicarboxybenzidine yields the corresponding salts of4,4'-bisdiazobiphenyl, 4,4'-bisdiazo,3,3'-dichlorobiphenyl,4,4'-bisdiazo-3,3'-dimethylbiphenyl, 4,4'-bisdiazo-2,2'-disulfobiphenyl,and 4,4'-bisdiazo-3,3'-dicarboxybiphenyl.

EXAMPLE 6 Naphthalenesulfonic Acid Compounds, Formula XI

Benzidine (0.5 g, 2.7 mmol) was slurried in 20 mL of water containing 1mL of 12 M HCl at 0° C. Sodium nitrite (0.38 g, 5.4 mmol) in 5 mL ofwater was added with vigorous stirring, yielding the bisdiazobenzidine.The solution was diluted to 100 mL with water at 0° C.4-Aminonaphthalene-1-sulfonic acid (0.61 g, 2.7 mmol) was dissolved in25 mL of water by adding a minimum amount of 1 M NaOH to dissolve allsolids. The solution was chilled to 0° C.

The solution of the 4-aminonaphthalene-1-sulfonic acid was addeddropwise to the solution of bisdiazobenzidine with concurrent dropwiseaddition of 1 M NaOH to maintain the pH between 6 and 7. After 30 min ofstirring, a solution of 2-iodophenol (0.60 g, 2.7 mmol) in 5 mL of waterwith enough 1 M NaOH to dissolve all solids was added at once. The pH ofthe mixture was adjusted to pH 11 by addition of 1 M NaOH and stirredfor 15 min. The product was isolated by rotoevaporation and purified bycolumn chromatography using silica gel and eluting with 85:15 v/vdichloromethane/methanol to yield3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid. ¹ H (D₆ -DMSO/D₂ O 250 Mhz) delta 8.69 (d, naphthyl-H), 8.37 (d,naphthyl-H), 8.26 (S, naphthyl-H), 8.18 (S, phenyl-H), 7.86 (d,benzidine-H), 7.80 (d, phenyl-H), 7.73 (d, benzidine-H), 7.1 (t,t,naphthyl-H), 7.39 (d,d, benzidine-H), 7.02 (d, phenyl-H).

EXAMPLE 7 Naphthalenesulfonic Acid Compounds, Formula XI

Repeating the procedure of Example 6 but replacing the

4-aminonaphthalene-1-sulfonic acid with

4-amino-5-hydroxynaphthalene-1-sulfonic acid, and

4-amino-5-hydroxynaphthalene-2,7-disulfonic acid and maintaining

the pH of the first coupling reaction between 3 and 7 yields thecorresponding, respective,

3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-biphen-4'-yldiazo)-4-amino-5-hydroxynaphthalene-1-sulfonicacid, and

3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-biphen-4'-yldiazo)-4-amino-5-hydroxynaphthalene-2,7-disulfonicacid.

EXAMPLE 8 Naphthalenesulfonic Acid Compounds, Formula XI

Repeating the procedure of Example 6 but replacing the

4-aminonaphthalene-1-sulfonic acid with

4-amino-5-hydroxynaphthalene-1-sulfonic acid,

4-amino-5-hydroxynaphthalene-1,3-disulfonic acid, and

4-amino-5-hydroxynaphthalene-2,7-disulfonic acid and maintaining the pHof the first coupling reaction between 8 and 11 yields thecorresponding, respective,

6-(4-(1-hydroxy-2-iodophen-4-yldiazo)-biphen-4'-yldiazo)-4-amino-5-hydroxynaphthalene-1-sulfonicacid,

6-(4-(1-hydroxy-2-iodophen-4-yldiazo)-biphen-4'-yldiazo)-4-amino-5-hydroxynaphthalene-1,3-disulfonicacid, and

6-(4-(1-hydroxy-2-iodophen-4-yldiazo)-biphen-4'-yldiazo)-4-amino-5-hydroxynaphthalene-2,7-disulfonicacid.

EXAMPLE 9 Naphthalenesulfonic Acid Compounds, Formula XI

Repeating the procedure of Example 6 but replacing the benzidine with3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 3,3'-dichlorobenzidine,3,3'-dinitrobenzidine, benzidine-2,2'-disulfonic acid andbenzidine-3,3'-dicarboxylic acid yields the following, respective,

3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-3,3'-dimethylbiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-3,3'-dimethoxybiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-3,3'-dichlorobiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-3,3'-dinitrobiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid, and

3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-3,3'-disulfobiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid.

EXAMPLE 10 Napthalenesulfonic Acid Compounds, Formula XI

Repeating the procedure of Example 6 but replacing the 2-iodophenol with4-iodophenol, 4-iodo-2-methylphenol, 4-iodo-2-methoxyphenol,2-carboxy-4-iodophenol, 2-hydroxy-5-iodobenzoic acid, methyl2-hydroxy-5-iodobenzoate, 2-iodo-6-methylphenol, 2-iodo-6-methoxyphenol,2-hydroxy-3-iodobenzoic acid, methyl 2-hydroxy-3-iodobenzoate,2-iodo-4-methylphenol, 2-iodo-4-methoxyphenol, 4-hydroxy-3-iodobenzoicacid, methyl 4-hydroxy-3-iodobenzoate, phenol, 4-methylphenol,4-methoxyphenol, 4-hydroxybenzoic acid, methyl 4-hydroxybenzoate,2-methylphenol, 2-methoxyphenol, 2-hydroxybenzoic acid, and methyl2-hydroxybenzoate, yields the corresponding, respective,

3-(4-(1-hydroxy-4-iodophen-2-yldiazo)-biphen-4'-yldiazo)-4-amino-naphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-iodo-2-methylphen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-iodo-2-methoxyphen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene--sulfonicacid,

3-(4-(1-carboxy-2-hydroxy-5-iodophen-3-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-hydroxy-5-iodo-1-methyloxycarbonyl-phen-3-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1sulfonicacid,

3-(4-(1-hydroxy-2-iodo-6-methylphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1sulfonicacid,

3-(4-(1-hydroxy-2-iodo-6-methoxyphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-hydroxy-3-iodophen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-hydroxy-3-iodo-1-methyloxycarbonyl-phen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo-4-methylphen-6-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo-4-methoxyphen-6-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-4-hydroxy-3-iodophen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(4-hydroxy-3-iodo-1-methyloxycarbonylphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydrophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-methylphen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-methoxyphen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-4-hydroxyphen-3-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(4-hydroxy-1-methyloxycarbonylphen-3-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-methylphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-methyloxyphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-2-hydroxyphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid, and

3-(4-(2-hydroxy-1-methyloxycarbonylphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid.

EXAMPLE 11 Napthalenesulfonic Acid Compounds, Formula XI

Repeating the procedure of Example 6 but replacing 2-iodophenol withN-methyl-2-iodoaniline, N,N-dimethyl-2-iodoaniline, N-methylaniline andN,N-dimethylaniline and maintaining the pH of the solution at 5-7 duringthe second diazo coupling yields the corresponding

3-(4-(2-iodo-1-methylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-iodo-1,1-dimethylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-methyaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-dimethylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid.

EXAMPLE 12 Napthalenesulfonic Acid Compounds, Formula XI

Repeating the procedure of Example 2 but replacing BOR with

3-(4-(1-hydroxyphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-methylphen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-methoxyphen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-4-hydroxyphen-3-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(4-hydroxy-1-methyloxycarbonylphen-3-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-methylphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-methoxyphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-2-hydroxyphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-hydroxy-1-methyloxycarbonylphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-methylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid, and

3-(4-(1,1-dimethylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid yields the corresponding, respective iodinated compounds,

3-(4-(1-hydroxy-2-iodophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo-4-methylphen-6-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo-4-methoxphen-6-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-4-hydroxy-3-iodophen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(4-hydroxy-3-iodo-1-methyloxycarbonylphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo-6-methylphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo-6-methoxyphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-2-hydroxy-3-iodophen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-hydroxy-3-iodo-1-methyloxycarbonylphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-iodo-1-methylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-iodo-1,1-dimethylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid.

EXAMPLE 13 Napthalenesulfonic Acid Compounds, Formula XI

Repeating the procedure of Example 3 but replacing IBOR with theproducts of Examples 6 to 10 yields the corresponding, respective, ¹²⁵ Iand ¹²³ I products wherein iodo(^(*)) represents either ¹²⁵ I or ¹²³ I:

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-biphen-4'-yldiazo)-4-amino-5-hydroxynaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-biphen-4'-yldiazo)-4-amino-5-hydroxynaphthalene-1,3-disulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-biphen-4'-yldiazo)-4-amino-5-hydroxynaphthalene-2,7-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-3,3'-dimethylbiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-3,3'-dimethoxybiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-3,3'-dichlorobiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-3,3'-dinitrobiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-2,2'-disulfobiphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-iodo(^(*))phen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-iodo(^(*))-2-methylphen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-4-iodo(^(*))-2-methoxyphen-2-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-2-hydroxy-5-iodo(^(*))phen-3-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-hydroxy-5-iodo(^(*))-1-methyloxycarbonyl-phen-3-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))-6-methylphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))-6-methoxyphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-2-hydroxy-3-iodo(^(*))phen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-hydroxy-3-iodo(^(*))-1-methyloxycarbonyl-phen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))-4-methylphen-6-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))-4-methoxyphen-6-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-4-hydroxy-3-iodo(^(*))phen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(4-hydroxy-3-iodo(^(*))-1-methylcarbonylphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-iodo(^(*))-1-methylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(2-iodo(^(*))-1,1-dimethylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))-4-methylphen-6-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))-4-methoxyphen-6-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-4-hydroxy-3-iodo(^(*))phen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(4-hydroxy-3-iodo(^(*))-1-methyloxycarbonylphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))-6-methylphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-hydroxy-2-iodo(^(*))-6-methoxyphen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(1-carboxy-2-hydroxy-3-iodo(^(*))phen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(4-(2-hydroxy-3-iodo(^(*))-1-methyloxycarbonylphen-5-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid,

3-(2-iodo(^(*))-1-methylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid, and

3-(2-iodo(^(*))-1,1-domethylaminophen-4-yldiazo)-biphen-4'-yldiazo)-4-aminonaphthalene-1-sulfonicacid.

EXAMPLE 14 Preparation of Direct Blue 4

1.0 g (4.1 mmole) of 3,3'-dimethoxybenzidine (Aldrich Chemical Co.,Milwaukee, Wis.) is slurried in 20 mL of water containing 2 mL of 12 MHCl at 0° C. To this mixture is added 0.56 g (8.2 mmole) of sodiumnitrite, giving a red solution of bis-diazo-3,3'-dimethoxybenzidine.This solution is added with vigorous stirring to a solution of 2.0 g(8.4 mmol) 4-amino-5-hydroxynaphthalene-1-sulfonic acid in 200 mL ofwater adjusted to pH 10 with 1 M NaOH. A deep blue color forms rapidly,and stirring is continued for 1 hr. The pH of the mixture is adjusted to7.0, and the solvent is removed by rotoevaporation.

The product is purified by dissolving the blue solid in a minimum amountof methanol with a few drops of 1 M NaOH. The solution is spotted on 20cm×20 cm C₁₈ silica reverse phase TLC plates and eluted with 80:20:0.1v/v/v methanol/water/trifluoacetic acid. The product is isolated fromthe silica by extraction with methanol, followed by evaporation to yield6,6'-(3,3'-dimethoxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxynaphthalene-1-sulfonicacid).

EXAMPLE 15 Radioiodinated Chicago Sky Blue 6B (CSB)

0.20 g (0.20 mmole) of CSB was dissolved in 7 mL of water. Anothersolution containing 0.30 g (0.2 mmole) NaI, 0.056 g (0.20 mmole)Chloramine-T, and 0.20 mCi Na¹²⁵ I in 4 mL of water was added to thesolution of CSB with vigorous stirring for 30 min. giving a 4-5% yieldof mono-radioiodinated CBS (of Formula II).

Repeating this procedure with NaI (non-radioactive) and Na¹²³ I yieldsthe corresponding monoiodinated and mono-radioiodinated CBS of FormulaXIV and Formula II,6,6'-((3,3'-dimethoxybiphen-4,4'-diyl)bis(diazo)bis(4-amino-5-hydroxy-8-iodonaphthalene-1,3-disulfonicacid, sodium salt.

Repeating these procedures but replacing CSB with the Direct Blue 4product of Example 12 yields the corresponding mono-radioiodinatedDirect Blue 4 product.

EXAMPLE 16 Dinaphthyldiazobiphenyl compounds (Formula XIV)

Repeating the procedure of Example 14 at pH 3 to 7, but replacing3,3'-dimethoxybenzidine with benzidine, 3,3'-dichlorobenzidine,3,3'-dimethylbenzidine, 3,3'-dicarboxybenzidine, and2,2'-disulfobenzidine yields the corresponding, respective sodium saltsof

3,3'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dicarboxyphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1-naphthalenesulfonicacid).

Repeating the above procedure at pH 10 yields the corresponding sodiumsalts of

6,6'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1naphthalenesulfonicacid);

6,6'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1naphthalenesulfonicacid);

6,6'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1naphthalenesulfonicacid);

6,6'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1naphthalenesulfonicacid);

6,6'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-5-hydroxy-1naphthalenesulfonicacid).

EXAMPLE 17 Iodinated Dinaphthyldiazobiphenyl Compounds (Formulas II andXIV)

Repeating the procedure of Example 15, but replacing the Chicago SkyBlue with the products of Example 16 yields the corresponding respectiveiodine and radiolabeled ¹²³ I and ¹²⁵ I substituted

3,3'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid).

EXAMPLE 18 Iodinated Dinaphthyldiazobiphenyl Compounds (Formulas II andXIV)

Chicago Sky Blue 6B (0.85 g, 0.086 mmol) is slurried in 5 mL ofanhydrous methanol. A solution of 0.14 g (0.086 mmole) of ICl (Aldrich)in 1 mL of methanol is added with vigorous stirring. After one hour ofstirring, the product is isolated by rotoevaporation. Purification ofthe product is accomplished by preparative RPTLC to yield the iodinatedChicago Sky Blue, a compounds of Formula XIV.

Repeating the procedure but replacing the ICl with ¹²³ ICl yields thecorresponding radiodinated Chicago Sky Blue, a compound of Formula II.

Repeating the above procedure, but replacing the Chicago Sky Blue withthe products of Example 14 yields the corresponding respective iodineand radiolabeled ¹²³ I and ¹²⁵ I substituted3,3'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

3,3'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid);

6,6'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonicacid).

EXAMPLE 19 Radioiodinated Dinaphthyldiazobiphenyl Compounds (Formula II)

The iodinated Chicago Sky Blue 6B product of Example 15 (substitutedwith non-radioactive iodine) 0.992 mg (0.1 mmole) is stirred in 1 mL ofabsolute ethanol in a high pressure reaction flask fitted with a tefloncap. Na¹²³ I, 0.2-10 mCi is added, and the flask is sealed. The mixtureis heated to 150° C. for 6-18 hr. The product is purified by preparativeRPTLC or HPLC to yield the radioiodine substituted CSB product ofFormula II.

Repeating this procedure but substituting the iodinated CSB withproducts of non-radioactive iodine substituted products of Example 14yields the corresponding radioiodine substituted

3,3'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonic acid);

3,3'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonic acid);

3,3'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthalenesulfonic acid);

3,3'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-6-iodo-5-hydroxy-1-naphthal -naphthalenesulfonic acid);

3,3'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid);

3,3'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid);

3,3'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid);

3,3'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid);

6,6'-(biphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid);

6,6'-(3,3'-dichlorobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid);

6,6'-(3,3'-dimethylbiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid);

6,6'-(3,3'-dicarboxybiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid);

6,6'-(2,2'-disulfobiphenyl-4,4'-diyl)bis(azo)bis(4-amino-8-iodo-5-hydroxy-1-naphthalenesulfonic acid).

EXAMPLE 20 Amino-3-(4-iodophenylazo)-naphthylenesulfonic acids FormulaXVI

4-Iodoaniline (5 g, 22.8 mmole) was dissolved in 100 mL of THF andchilled to -5° C. 5 mL (40.6 mmole) of boron trifluoride etherate wasadded with stirring, followed by 4 mL (33.6 mmole) of t-butylnitrite.Stirring at -5° C. was continued for 45 min. A white crystalline solidwas collected by filtration and rinsed with 20 mL of THF and 2 mLportions of diethyl ether. The resulting tetrafluoroborate salt ofdiazo-4-iodobenzene was dried in vacuo to give a yield of 88%.

Diazo-4-iodobenzene (2.0 g, 6.3 mmole) was dissolved in 10 mL ofacetonitrile. 4-Aminonaphthalene-1-sulfonic acid, sodium salt dihydrate(1.85 g, 6.6 mmole), and sodium bicarbonate (0.55 g, 6.5 mmole) weredissolved together in 25 mL of water and then diluted to 100 mL withmethanol. The two solutions were combined with vigorous stirring, givingan orange-red solution. After 1 hr of stirring, the solution volume wasreduced to 20 mL by rotoevaporation. The resulting red precipitate wascollected by filtration and rinsed with 20 mL of acetonitrile. Theproduct is dried in vacuo to give a 74% yield of4-amino-3-(1-iodo-phen-4 -yldiazo)-naphthylene-1-sulfonic acid. Furtherpurification was accomplished by preparative RPTLC. ¹ H NMR (D₆ -DMSO/D₂O, 250 Mhz) delta 8.69 (d,naphthyl-H), 8.39 (d, naphthyl-H), 8.26 (S,naphthyl-H), 7.86 (d,phenyl-H), 7.75 (d, phenyl-H), 7.58 (t,naphthyl-H), 7.51 (t,naphthyl-H).

EXAMPLE 21 3-(4-iodophenylazo)-naphthylenesulfonic acids Formula XVI

Repeating the procedure of Example 20 but replacing 4-aminonaphthalene-1-sulfonic acid with 4-amino-5-hydroxynaphthylene-1-sulfonic acid;4-amino-5-hydroxynaphthalene-1,3-disulfonic acid; and1-amino-8-hydroxynaphthylene-3,6-disulfonic acid yields thecorresponding, respective

4-5-hydroxy-3-(1-iodophen-4-yldiazo)-naphthylene-1-sulfonic acid;

4-5-hydroxy-6-(1-iodophen-4-yldiazo)-naphthylene-1-sulfonic acid;

4-5-hydroxy-6-(1-iodophen-4-yldiazo)-naphthylene-1,3-disulfonic acid;

4-5-hydroxy-7-(1-iodophen-4-yldiazo)-naphthylene-2,7-disulfonic acid;

4-5-hydroxy-2-(1-iodophen-4-yldiazo)-naphthylene-2,7-disulfonic

EXAMPLE 22 Substituted Naphthylene-1-sulfonic acids Formula XVI

Repeating the procedure of Example 20 but replacing

4-iodoaniline with 2-iodoaniline, 3-iodoaniline,

2-amino-4-iodotoluene with 2-amino-5-iodotoluene,

4-amino-2-iodotoluene, and 2-amino-4-iodobenzoic acid yields thecorresponding, respective,

4-amino-3-(1-iodophen-2-yldiazo)-naphthylene-1-sulfonic acid,

4-amino-3-(1-iodophen-3-yldiazo)-naphthylene-1-sulfonic acid,

4-amino-3-(1-iodo-4-methylphen-3-yldiazo)-naphthylene-1-sulfonic acid,

4-amino-3-(1-iodo-3-methylphen-4-yldiazo)naphthylene-1-sulfonic acid,and

4-amino-3-(1-carboxy-3-iodophen-2-yldiazo)-naphthylene-1-sulfonic acid.

EXAMPLE 23 3-(4-iodo(^(*))-phenylazo)-naphthylenesulfonic acids FormulaIII

10 Mg of the product of Example 20 and Na¹²⁵ I were slurried in 1 mL ofabsolute ethanol in a high pressure flask fitted with a teflon cap. Themixture was heated to 150° C. for 18 hr, giving radiochemical yield of70%. The labeled dye was purified by RPTLC to yield 4-amino-3-(4-¹²⁵I-phenyldiazo)-naphthylene-1-sulfonic acid.

Repeating this procedure with Na¹²³ I yields the corresponding4-amino-3-(4-¹²³ I-phenyldiazo)-naphthylene-1-sulfonic acid.

EXAMPLE 24 (iodo(^(*))-phenylazo)-naphthylenesulfonic acids Formula III

Repeating the procedure of Example 22 with the products of Examples 20and 21 yields the corresponding, respective, ¹²⁵ I and ¹²³ I productswherein iodo(^(*)) represents either ¹²⁵ I or ¹²³ I:

4-amino-5-hydroxy-3-(1-iodo(^(*))-phen-4-yldiazo)-naphthylene-1-sulfonicacid;

4-amino-5-hydroxy-6-(1-iodo(^(*))-phen-4-yldiazo)-naphthylene-1-sulfonicacid;

4-amino-5-hydroxy-6-(1-iodo(^(*))-phen-4-yldiazo)-naphthylene-1,3-disulfonicacid;

1-amino-8-hydroxy-7-(1-iodo(^(*))-phen-4-yldiazo)-naphthylene-3,6-disulfonicacid;

1-amino-8-hydroxy-2-(1-iodo(^(*))-phen-4-yldiazo)-naphthylene-3,6-disulfonicacid;

4-amino-3-(1-iodo(^(*))-phen-2-yldiazo)-naphthylene-1-sulfonic acid,

4-amino-3-(1-iodo(^(*))-phen-3-yldiazo)-naphthylene-1-sulfonic acid,

4-amino-3-(1-iodo(^(*))-phen-4-yldiazo)-naphthylene-1-sulfonic acid,

4-amino-3-(1-iodo(^(*))-methylphen-4-yldiazo)-naphthylene-1-sulfonicacid, and

4-amino-3-(1-carboxy-3-iodo(^(*))-phen-2-yldiazo)-naphthylene-1-sulfonicacid.

EXAMPLE 25 2-(4-diazophenyl)-6-methylbenzothiazole-7-sulfonic acidFormula XVIII

2-94-Aminophenyl)-6-methylbenzothiazole-7-sulfonic acid (2.0 g, 6.2mmole) was dissolved in 60 mL of water at pH 6.0 and chilled to 0° C. inan ice/ethanol bath. Sodium nitrite (0.51 g, 7.4 mmole) in 5 mL of waterwas added with stirring. 3.0 ML of 12 M hydrochloric acid (36 mmole) wasadded with vigorous stirring, yielding an orange-yellow precipitate ofthe diazonium salt, 2-(4-diazophenyl)-6-methylbenzothiazole-7-sulfonicacid, sodium salt. The product is preferably used within 10 min ofpreparation.

EXAMPLE 26 2-(4-diazophenyl)-6-methylbenzothiazole Formula XVIII

2-(4-Aminophenyl)-6-methylbenzothiazole (10.0 g, 41.6 mmole) wasdissolved in 200 mL of anhydrous THF and chilled to -15° C. under anitrogen atmosphere. Boron trifluoride etherate (15 mL, 122 mmole) wasadded with stirring to give a homogenous solution. T-butylnitrite (7.5ml, 63 mmole) was added to the solution, and the mixture was stirred for1 hr. A yellow precipitate was collected by filtration and rinsed with75 mL of ether. After drying in vacuo, a 94% yield of the diazoniumsalt, 2-(4-diazophenyl)-6-methylbenzothiazole, boron tetrafluoride saltwas obtained.

EXAMPLE 27 2-(4-diazophenyl)-benzothiazole-6-carboxylic acid FormulaXVIII

Repeating the procedure of Example 25 but replacing2-(4-aminophenyl)-6-methylbenzothiazole-7-sulfonic acid with2-(4-aminophenyl)-6-carboxybenzothiazole yields the corresponding saltof 2-(4-diazophenyl)-benzothiazole-6-carboxylic acid.

EXAMPLE 282-(4-(1-hydroxy-2-iodophen-4-yldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid, Formula XX

The product of Example 24 (6.2 mmole) was added to a solution of 1.54 g(7.0 mmole) of 2-iodophenol in 100 mL of solvent (water of 1:1water:acetonenitrile) containing 14 mmole of sodium hydroxide. Thesolution was stirred at 21° C. for 2 hr maintained at pH 11 and then wasacidified to pH 7.0. The solvent was removed by rotoevaporation, and theremaining solid was washed with acetonitrile, collected by filtrationand dried in vacuo yielding 60-85% of2-(4-(1-hydroxy-2-iodophen-4-yldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid. The product was purified by reverse phase TLC to give purities ofabove 99%. ¹ H NMR (D₄ -Methanol/NaOD, 250 MHz) delta 7.59 (S, Ar-H),7.48, 7.26, 7.17, 7.04, 7.00, 6.76, 5.96 (d,d,d,d,d,d,d, Ar-H), 2.13 (S,CH₃ -).

EXAMPLE 29 2-(4-(phenyldiazo)-phenyl)-benzothiazoles Formula XX

Repeating the procedure of Example 28 but replacing 2-iodophenol with4-iodophenol, 4-iodo-2-methylphenol, 4-iodo-2-methoxyphenol,2-carboxy-4-iodophenol, 2-hydroxy-5-iodobenzoic acid, methyl2-hydroxy-5-iodobenzoate, 2-iodo-6-methylphenol, 2-iodo-6-methoxyphenol,2-hydroxy-3-iodobenzoic acid, methyl 2-hydroxy-3-iodobenzoate,2-iodo-4-methylphenol, 2-iodo-4-methoxyphenol, 4-hydroxy-3-iodobenzoicacid, methyl 4-hydroxy-3-iodobenzoate, phenol, 4-methylphenol,4-methoxyphenol, 4-hydroxybenzoic acid, methyl 4-hydroxybenzoate,2-methylphenol, 2-methoxyphenol, 2-hydroxybenzoic acid and methyl2-hydroxybenzoate yields the corresponding, respective,

2-(4-(1-hydroxy-4-iodophen-2-yldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-4-iodo-2-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-4-iodo-2-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-2-hydroxy-5-iodo-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-hydroxy-5-iodo-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-2-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid

2-(4-(1-carboxy-4-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(4-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-4-methyl-2-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-4-hydroxy-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(4-hydroxy-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-2-hydroxy-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-hydroxy-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid.

EXAMPLE 30 2-(4-(phenyldiazo)-phenyl)-benzothiazoles Formula XX

Repeating the procedure of Example 28 but replacing the 2-iodophenolwith N-methyl-2-iodoaniline, N,N-dimethyl-2-iodoaniline, N-methylanilineand N,N-dimethylaniline and maintaining the solution at pH 5 to 7 yieldsthe corresponding

2-(4-(2-iodo-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-dimethylamino-2-iodo-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid, and

2-(4-(1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid.

EXAMPLE 31 2-(4-(phenyldiazo)-phenyl)-benzothiazolecarboxylic acidsFormula XX

Repeating the procedure of Example 28 but replacing the product ofExample 25 with the products of Example 27, and replacing 2-iodophenolwith 4-iodophenol, 4-iodo-2-methylphenol, 4-iodo-2-methoxyphenol,2-carboxy-4-iodophenol, 2-hydroxy-5-iodobenzoic acid, methyl2-hydroxy-5-iodobenzoate, 2-iodo-6-methylphenol, 2-iodo-6-methoxyphenol,2-hydroxy-3-iodobenzoic acid, methyl 2-hydroxy-3-iodobenzoate,2-iodo-4-methylphenol, 2-iodo-4-methoxyphenol, 4-hydroxy-3-iodobenzoicacid, methyl 4-hydroxy-3-iodobenzoate, phenol, 4-methylphenol,4-methoxyphenol, 4-hydroxybenzoic acid, methyl 4-hydroxybenzoate,2-methylphenol, 2-methoxyphenol, 2-hydroxybenzoic acid, methyl2-hydroxybenzoate, yields the corresponding, respective,

2-(4-(1-hydroxy-4-iodophen-2-yldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-4-iodo-2-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-4-iodo-2-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-2-hydroxy-5-iodo-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(2-hydroxy-5-iodo-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid;

2-(4-(1-hydroxy-2-iodo-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-2-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(2-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-4-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(4-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-4-methyl-2-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-4--methoxy-2-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-4-hydroxy-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(4-hydroxy-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-2-hydroxy-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid, and

2-(4-(2-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid.

EXAMPLE 32 2-(4-(phenyldiazo)-phenyl)-benzothiazolecarboxylic acidsFormula XX

Repeating the procedure of Example 28 but replacing the product ofExample 25 with the products of Example 27, and replacing 2-iodophenolwith N-methyl-2-iodoaniline, N,N-dimethyl-2-iodoaniline, N-methylanilineand N,N-dimethylaniline and without adding sodium hydroxide (thusmaintaining the solution pH within the range of 5 to 7) yields thecorresponding

2-(4-(2-iodo-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(1-dimethylamino-2-iodo-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid.

EXAMPLE 33 2-(4-(phenyldiazo)-phenyl)-benzothiazoles Formula XX

2-Iodophenol (2.6 g, 11.8 mmol) was dissolved in 200 mL of 1:1acetonitrile/water containing 14 mL of 1 M sodium hydroxide.2-(4-Diazophenyl)-6-methylbenzothiazole (4.07 g, 12.0 mmol) was added asa solid with vigorous stirring. After 12-18 hr of stirring, the azo dyewas precipitated with 1 mL of glacial acetic acid followed by rinsingwith ethanol and diethylether. The dye was dried in vacuo. Purificationof the dye was accomplished by NPTLC eluted with 90:10dichloromethane:methanol to yield2-(4-(1-hydroxy-2-iodophen-4-yldiazo)-phenyl)-6-methylbenzothiazole.

¹ H NMR (D₆ -DMSO, 400 MHz) delta 8.27 (S, Ar-H), 8.24 (d, Ar-H), 7.97(d,d, Ar-H), 7.95 (S, Ar-H), 7.88 (d, Ar-H), 7.38 (d, Ar-H), 7.08 (d,Ar-H), 2.46 (S, Ar-CH₃).

EXAMPLE 34 2-(4-(phenyldiazo)-phenyl)-benzothiazoles Formula XX

Repeating the procedure of Example 33 but replacing 2-iodophenol with4-iodophenol, 4-iodo-2-methylphenol, 4iodo-2-methoxyphenol,2-carboxy-4-iodophenol, 2-hydroxy-5-iodobenzoic acid, methyl2-hydroxy-5-iodobenzoate, 2-iodo-6-methylphenol, 2-iodo-6-methoxyphenol,2-hydroxy-3-iodobenzoic acid, methyl 2-hydroxy-3-iodobenzoate,2-iodo-4-methylphenol, 2-iodo-4-methoxyphenol, 4-hydroxy-3-iodobenzoicacid, methyl 4-hydroxy-3-iodobenzoate, phenol, 4-methylphenol,4-methoxyphenol, 4-hydroxybenzoic acid, methyl 4-hydroxybenzoate,2-methylphenol, 2-methoxyphenol, 2-hydroxybenzoic acid and methyl2-hydroxybenzoate, yields the corresponding, respective,

2-(4-(1-hydroxy-4-iodophen-2-yldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-4-iodo-2-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-4-iodo-2-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-2-hydroxy-5-iodo-3-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-hydroxy-5-iodo-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-2-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-4-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(4-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-4-methyl-2-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-4-methoxy-2-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-4-hydroxy-3-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(4-hydroxy-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-2-hydroxy-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,and

2-(4-(2-hydroxy-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole.

EXAMPLE 35 2-(4-(phenyldiazo)-phenyl)-benzothiazoles Formula XX

Repeating the procedure of Example 33 but replacing 2-iodophenol withN-methyl-2-iodoaniline, N,N-dimethyl-2-iodoaniline, N-methylaniline andN,N-dimethylaniline yields the corresponding2-(4-(2-iodo-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,2-(4-(1-dimethylamino-2-iodo-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,2-(4-(1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole, and2-(4-(1,1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid.

EXAMPLE 36 2-(4-(iodophenyldiazo)-phenyl)-benzothiazoles Formulas XX andIV

Repeating the procedure of Example 2, but replacing BOR with thenon-iodinated products of Examples 28-35 yields the following iodinatedcompounds, the iodo group being non-radioactive iodo, ¹²³ I or ¹²⁵ I,depending upon whether the iodine source is non-radioactive ICl, ¹²³ IClor ¹²⁵ ICl:

2-(4-(1-hydroxy-2-iodo-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzo-thiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzo-thiazole-7-sulfonicacid,

2-(4-(1-carboxy-3-iodo-4-hydroxy-5-phenyldiazo)-phenyl)-6-methylbenzo-thiazole-7-sulfonicacid,

2-(4-(4-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-2-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-iodo-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-iodo-1,1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-4-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(4-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-2-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-iodo-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-iodo-1,1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo-2-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-4-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(4-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-2-hydroxy-3-iodo-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(2-hydroxy-3-iodo-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(2-iodo-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid, and

2-(4-(2-iodo-1,1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid.

EXAMPLE 37 2-(4-(iodophenyldiazo)-phenyl)-benzothiazoles Formula IV

Repeating the iodine exchange procedure of Example 3 but replacing theIBOR with the non-radioactive iodinated products of Examples 27-35yields the following ¹²⁵ I and ¹²³ I products wherein iodo(^(*))represents either ¹²⁵ I or ¹²³ I:

2-(4-(1-hydroxy-2-iodo(^(*))phen-4-yldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-4-iodo(^(*))phen-2-yldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-4-iodo(^(*))-2-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-4-iodo(^(*))-2-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-2-hydroxy-5-iodo(^(*))-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-hydroxy-5-iodo(^(*))-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-2-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-4-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(4-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-methylamino-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1,1-dimethylamino-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-4-iodo(^(*))phen-2-yldiazo)-phenyl)-6-methylbenzothiazole

2-(4-(1-hydroxy-4-iodo(^(*))-2-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-4-iodo(^(*))-2-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-2-hydroxy-5-iodo(^(*))-3-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-hydroxy-5-iodo(^(*))-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-2-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-4-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(4-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(1-methylamino-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1,1-dimethylamino-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-4-iodo(^(*))phen-2-yldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-4-iodo(^(*))-2-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-4-iodo(^(*))-2-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-2-hydroxy-5-iodo(^(*))-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(2-hydroxy-5-iodo(^(*))-1-methoxycarbonyl-3-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-2-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(2-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-carboxy-4-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(4-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-methylamino-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1,1-dimethylamino-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-3-iodo(^(*))-4-hydroxy-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(4-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-carboxy-2-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-iodo(^(*))-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(2-iodo(^(*))-1,1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole

2-(4-(1-hydroxy-2-iodo(^(*))-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methoxy-6-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-4-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(4-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(1-carboxy-2-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-iodo(^(*))-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole,

2-(4-(2-iodo(^(*))-1,1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-7-sulfonicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methyl-6-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxylicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-4-methoxy-2-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilicacid,

2-(4-(1-carboxy-4-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilicacid,

2-(4-(4-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methyl-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilicacid,

2-(4-(1-hydroxy-2-iodo(^(*))-6-methoxy-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilicacid,

2-(4-(1-carboxy-2-hydroxy-3-iodo(^(*))-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilic acid,

2-(4-(2-hydroxy-3-iodo(^(*))-1-methoxycarbonyl-5-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilicacid,

2-(4-(2-iodo(^(*))-1-methylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilicacid, and

2-(4-(2-iodo(^(*))-1,1-dimethylamino-4-phenyldiazo)-phenyl)-6-methylbenzothiazole-6-carboxilicacid.

We claim:
 1. An amyloid binding diazo compound of Formula III or FormulaIV or a water-soluble non-toxic salt thereof: ##STR13## wherein: I^(*)is a radioactive iodine moiety;R₄₀ R₄₁ are hydrogen hydroxy or amino,and R₄₀ and R₄₁ are not the same group; R₄₂, R₄₃, R₄₄, R₄₅ and R₄₆ aresulfo; and sulfo is not present on adjacent carbons; and R₄₇ ishydrogen, methyl or carboxy.
 2. A method for determining the presenceand location of an amyloid deposit in a body area of a patientcomprising intravenous administration of an imaging effective quantityof a compound containing a radioactive iodine group of any one of claims16, 18, 19 or 24 to the patient, and sensing radiation emitted from thebody area.
 3. A method for determining the presence and location of anamyloid deposit in a body area of a patient comprising intravenousadministration of an imaging effective quantity of a compound containinga radioactive iodine group of anyone of claims 16-22 inclusive to thepatient, and sensing radiation emitted from the body area. 4.4-Amino-3-(1-¹²³ I-phen-4-yldiazo)-naphthylene-1-sulfonic acid or awater-soluble, non-toxic salt thereof.
 5. 4-Amino-3-(1-¹²⁵I-phen-4-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 6. 4-Amino-5-hydroxy-3-(1-¹²³I-phen-4-yldiazo)-naphthylene-1-sulfonic acid or a water soluble,non-toxic salt thereof.
 7. 4-Amino-5-hydroxy-3-(1-¹²⁵I-phen-4-yldiazo)-naphthylene-1-sulfonic acid or a water soluble,non-toxic salt thereof.
 8. 4-Amino-5-hydroxy-6-(1-¹²⁵I-phen-4-yldiazo)-naphthylene-1,3-disulfonic acid or a water-soluble,non-toxic salt thereof.
 9. 4-Amino-5-hydroxy-63-(1-¹²³I-phen-4-yldiazo)-naphthylene-1,3-disulfonic acid or a water-soluble,non-toxic salt thereof.
 10. 4-Amino-5-hydroxy-6-(1-¹²⁵I-phen-4-yldiazo-naphthylene-1,3-disulfonic acid or a water-soluble,non-toxic salt thereof.
 11. 1-Amino-8-hydroxy-7-(1-¹²³I-phen-4-yldiazo)-naphthylene-3,6-disulfonic acid or a water-soluble,non-toxic salt thereof.
 12. 1-Amino-8-hydroxy-7-(1-¹²⁵I-phen-4-yldiazo)-naphthylene-3,6-disulfonic acid or a water-soluble,non-toxic salt thereof.
 13. 1-Amino-8-hydroxy-2-(1-¹²³I-phen-4-yldiazo)-naphthylene-3,6-disulfonic acid or a water-soluble,non-toxic salt thereof.
 14. 1-Amino-8-hydroxy-2-(1-¹²⁵I-phen-4-yldiazo)-naphthylene-3,6-disulfonic acid or a water-soluble,non-toxic salt thereof.
 15. 4-Amino-3-(1-¹²³I-phen-2-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 16. 4-Amino-3-(1-¹²⁵I-phen-2-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 17. 4-Amino-3-(1-¹²³I-phen-3-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 18. 4-Amino-3-(1-¹²⁵I-phen-3-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 19. 4-Amino-3-(1-¹²³I-methylphen-3-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 20. 4-Amino-3-(1-¹²⁵I-methylphen-3-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 21. 4-Amino-3-(1-carboxy-3-¹²³I-phen-2-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 22. 4-Amino-3-(1-carboxy-3-¹²⁵I-phen-2-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.
 23. 4-Amino-5-hydroxy-3-(1-¹²³I-phen-4-yldiazo)-naphthylene-1-sulfonic acid or a water-soluble,non-toxic salt thereof.